1. Field of the Invention
This invention relates to a furnace for providing circulating heated air to an interior comfort space where the furnace is capable of being operated in one of four physical orientations, and is more particularly directed to a door which will remain upright when the furnace is either in the up or the down vertical orientation and will also be usable in either of the two possible horizontal orientations, namely left or right.
2. Description of the Prior Art
Under normal circumstances, securing a furnace door is an operation that needs to meet but a few requirements. The door must open easily but remain tightly and securely closed when not deliberately opened. This is due to the fact that furnaces are generally situated outside of ordinary living spaces as in, for example a basement or a closet, and so are apt to be exposed to large amounts of dust and dirt. It is desirable that such dust and dirt, as well as moisture, be kept out of the internal functioning portions of the furnace.
It is also desirable that a furnace door present a smooth external appearance without bolts or other hardware showing. This is true not only for the aesthetic appearance, at least of a new furnace, but also because external parts may become corroded.
A furnace door should also be easily removable, so as to provide complete access to the interior of the furnace for servicing. In addition, it is desirable that no parts have to be removed in order to detach the door. The removal of small parts takes time, as does their replacement, and they can become lost during the process of furnace repair. It is also desirable there be a detente so that the door cannot be opened so far as to accidentally be removed, especially by an unwary householder. Lastly, the door serves as a repository, both inside and out, for indicia of various types; these include the manufacturer's name and/or logo and various warning and informational stickers which may be critical to the owner and/or repair-person.
In the instant case, the furnace on which the door is to be attached is capable of operation in any one of four positions. The furnace may be installed vertically in either updraft or downdraft position, or horizontally, on either its left or its right side. Occasionally the direction of installation may not be known until the installer is actually on site.
Whether the furnace is installed in updraft or downdraft orientation, however, it is desirable for the door to be in an upright position. In this context this means that the door will always open from the top down. It also means that the indicia on the door are always right side up when the furnace is in a vertical position, and are thus easily readable. Thus the door should be reversible on site so that it remains upright whether the furnace is installed in a vertical up or a vertical down position.
In the observed prior art, doors are attached to the furnaces via clips, but this arrangement does not meet the requirements of different installation orientations.